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  #211 (permalink)  
Old 02-17-2010, 04:39 PM
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I'll try to get that done this weekend RED!

Today I did not get any dieseling when I shut off the engine. She runs good right now but I have been trying to figure out how to explain the "hesitation" between 1,200rpm to about 1,800rpm. It doesn't really!!! During a typical acceleration, when the rpm hits 1,200 the engine almost acts like its starving for something. Then when the rpm gets past about 1,800, its like nitros was added. The thing runs great after 1,800 rpm. During a hard acceleration its really noticable.

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  #212 (permalink)  
Old 02-17-2010, 05:57 PM
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Quote:
Originally Posted by Blue84JeepCJ7
During a typical acceleration, when the rpm hits 1,200 the engine almost acts like its starving for something. Then when the rpm gets past about 1,800, its like nitros was added. The thing runs great after 1,800 rpm. During a hard acceleration its really noticable.
Could be just coming "on the cam"...
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  #213 (permalink)  
Old 02-17-2010, 07:13 PM
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Quote:
Originally Posted by cobalt327
Could be just coming "on the cam"...
I'll accept that!
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  #214 (permalink)  
Old 02-18-2010, 04:36 AM
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does the hesitation aka "stumble" happen driving normal or are you mashing the pedal to the floor from a stop sign???
or is this a "at cruise" condition

(the carb secondaries are mechanical and you maybe using (need to use) enough linkage travel to tip into them,,,when the secondaries trap door see's enough velocity it opens and whoooosh there's a rush of power)


pull just a couple of easy to reach plugs and post what you find,,,white/light brown/black and wet/black and dry/whatever

Last edited by red65mustang; 02-18-2010 at 04:45 AM.
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  #215 (permalink)  
Old 02-20-2010, 09:44 AM
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Quote:
Originally Posted by red65mustang
blue,
repeat a test please:
(my post:you don't know that the dist is still set up in original factory tune up,,,24c max and all in at only 3k)

check to see what the base is set at very low idle rpms (my stupid mistake way back not telling you to do that!!!),,,,then read the total at steady 4500rpms...

it can't be 40t-24c=16b "and" 39t-27c=12b which you have posted,,,
hate to guess but when you set it to 39 it did not stay there,,,it got nudged to 36t while tightening,,,36-24=12 is most likely

or it does have very strong advance springs so the timing is not in till much higher rpms which "could be" to prevent ping
After one week of not messing with the engine I performed the following;
The base at 400rpm, couldnt get much lower. Thought it was 200rpm but relized I inadvertantly hit the 2 cycl button!!!

400rpm - Variation in timing jumping from 14.8 to 18.8
700rpm - BASE - 12.5 deg of timing
3,000 - 39 deg
4,000 - 39 deg

Lets see if I can explain this correctly, in my previous readings post as you described above, the vac adv plate was somewhat sticking and it may NOT have slipped back to the full retard while taking those readings. Who knows, could just be me again!!! May be the current reason for 39-24=27. The extra 3 deg may be from the sticking vac adv?

Anyhow!!

After the aforementioned readings, I lubed the vac adv plate inside the distributor with some LPS 2 and connected the vacuum advance. I also tested it again with a vacuum tester gauge and it still wanted to stick a little but readings were way up from 10-18 deg to get it to rotate. With the hex adjustments, its suppose to work between 5 to 10 inch of vacuum. This may make my timing inconsistent for a while until the plate moves enough to free it up correctly. SO far it only advances my timing 2 deg.

I wish I had another distributor to stick in just to see what the readings would be then!!!!!
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  #216 (permalink)  
Old 02-20-2010, 10:17 AM
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Quote:
Originally Posted by Blue84JeepCJ7
400rpm - Variation in timing jumping from 14.8 to 18.8
700rpm - BASE - 12.5 deg of timing
3,000 - 39 deg
4,000 - 39 deg

The reason you got varying readings at 400 RPM is because the engine is barely running. In fact, I am surprised that the engine actually ran that slow.

Idle RPM's are commonly set in the 650-750 RPM range in DRIVE if an automatic trans, in NEUTRAL if a standard trans. Engine RPM in PARK will be about 200 RPM higher and the timing will also read higher because some centrifugal advance will be introduced as the RPM's increase.

There have been three links posted pertaining to your distributor. The third link says that it has up to 28 degrees of centrifugal advance. It also states that it is adjustable in 1 degree increments.

Third Link

I was unable to locate just how this adjustment is made on your distributor. Your instruction sheet should give that info.

By adjusting how much centrifugal advance is in the distributor, you will then be able to set the initial timing to a preferred 16-18 degrees (for your combo) and limit the total mechanical to a preferred 36-38 degrees (again for your combo).

From what you have posted, your vacuum advance is not working correctly. It is either broken internally (leaking diaphram) or the mechanical linkage is in a bind or the adjustment screw has been limiting the internal travel. If you have a miti-vac unit (hand held vacuum pump) you can test/adjust the vacuum advance cannister. I suggest setting it to yield a max of 10 degrees additional advance when connected to full manifold source.

Quote:
Originally Posted by Blue84JeepCJ7
I wish I had another distributor to stick in just to see what the readings would be then!!!!!
Have you considered after 216 posts and about five weeks time that it might just be time to take it to a reputable mechanic that has a distributor machine where it can be checked/set to the curve you need for your combo?

Last edited by Frisco; 02-20-2010 at 11:12 AM.
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  #217 (permalink)  
Old 02-20-2010, 12:23 PM
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Quote:
Originally Posted by Frisco
The reason you got varying readings at 400 RPM is because the engine is barely running. In fact, I am surprised that the engine actually ran that slow.

Idle RPM's are commonly set in the 650-750 RPM range in DRIVE if an automatic trans, in NEUTRAL if a standard trans. Engine RPM in PARK will be about 200 RPM higher and the timing will also read higher because some centrifugal advance will be introduced as the RPM's increase.

There have been three links posted pertaining to your distributor. The third link says that it has up to 28 degrees of centrifugal advance. It also states that it is adjustable in 1 degree increments.

Third Link

I was unable to locate just how this adjustment is made on your distributor. Your instruction sheet should give that info.

By adjusting how much centrifugal advance is in the distributor, you will then be able to set the initial timing to a preferred 16-18 degrees (for your combo) and limit the total mechanical to a preferred 36-38 degrees (again for your combo).

From what you have posted, your vacuum advance is not working correctly. It is either broken internally (leaking diaphram) or the mechanical linkage is in a bind or the adjustment screw has been limiting the internal travel. If you have a miti-vac unit (hand held vacuum pump) you can test/adjust the vacuum advance cannister. I suggest setting it to yield a max of 10 degrees additional advance when connected to full manifold source.



Have you considered after 216 posts and about five weeks time that it might just be time to take it to a reputable mechanic that has a distributor machine where it can be checked/set to the curve you need for your combo?
One thing I won't be doing is digging into that distributor...lol I ain't going were I have no business being!!!! I gotta have this thing Monday morning to get to work! SUre, I could eventually do it, just don't have time to fix what I might break!

You guys have givin me a great understanding of what is going on but I'll leave it to the shop to make those internal adjustments! As soon as I can get some time, or someone whom I can trust, I'll get that done.

However to end this ongoing enjoyment of readying and from getting more of
Quote:
Have you considered after 216 posts and about five weeks time that it might just be time to take it to a reputable mechanic...
, I will no longer reply to this post.

To all who have taken their time to help....THANK!

Last edited by Blue84JeepCJ7; 02-20-2010 at 12:29 PM.
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  #218 (permalink)  
Old 02-20-2010, 01:03 PM
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Quote:
However to end this ongoing enjoyment of readying and from getting more of , I will no longer reply to this post.

To all who have taken their time to help....THANK!
Wham, bam, thank you ma'am! lol

In any event, I believe the solution is to be found within those 216 posts. Somewhere.

Good luck!
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  #219 (permalink)  
Old 02-23-2010, 07:15 AM
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blue,
39t-12b=27c means "somebody" has definitely torn the dist apart and changed the centrifugal settings....

found these instructions that explain to change cent you do dis-assemble down to the bottem plate and probably change the plates and screws stops arrangement for more/less travel...
(very likely the same cent change method/set up as they have used for years and it does work fine,,,contact accel to verify and get a copy of the install sheet which has a diagram)

http://www.accel-ignition.com/pdf/71000.pdf

the dist isn't likely broken,,,just set up and re-assembled wrong

PS: DON'T just unbolt and yank the dist,,,you want the motor set at TDC #1 and marks on the manifold so you can put it back in correct,,,rotor pointing to #1 and body roughly at 8-10btdc etc...

yup, at about this point I would be measuring to see what will it take to get enough clearance for a stock HEI dist diameter cap....
(LOL,,,10lb hammer on the firewall works great sometimes!)

drive safe,,,have fun

red

edit:
just for a clue for what I think the cent plates degrees change looks like here's a scan pic' of the old (dual points) accel body install sheet I do have
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Last edited by red65mustang; 02-23-2010 at 07:44 AM.
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  #220 (permalink)  
Old 02-23-2010, 03:18 PM
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Quote:
Originally Posted by red65mustang
blue,
39t-12b=27c means "somebody" has definitely torn the dist apart and changed the centrifugal settings....

found these instructions that explain to change cent you do dis-assemble down to the bottem plate and probably change the plates and screws stops arrangement for more/less travel...
(very likely the same cent change method/set up as they have used for years and it does work fine,,,contact accel to verify and get a copy of the install sheet which has a diagram)

http://www.accel-ignition.com/pdf/71000.pdf

the dist isn't likely broken,,,just set up and re-assembled wrong

PS: DON'T just unbolt and yank the dist,,,you want the motor set at TDC #1 and marks on the manifold so you can put it back in correct,,,rotor pointing to #1 and body roughly at 8-10btdc etc...

yup, at about this point I would be measuring to see what will it take to get enough clearance for a stock HEI dist diameter cap....
(LOL,,,10lb hammer on the firewall works great sometimes!)

drive safe,,,have fun

red

edit:
just for a clue for what I think the cent plates degrees change looks like here's a scan pic' of the old (dual points) accel body install sheet I do have
red thanks for that info. I will continue to learn and when I get a chance I will get this thing removed and fixed. It may not be broke but I'd like for it to be normal...lol!
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  #221 (permalink)  
Old 02-24-2010, 05:29 AM
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blue,
way way back I posted some oem dist's are set up with 28c not all in till 3800 approx on some heavy duty trucks,,,for no ping carrying or pulling a heavy load (with a oem stock truck cam designed for low end TQ) up a hill...

"fair chance" that was the "idea" when it was done,,,to help with the tall gears/weight/tires motor load imbalance...
(maybe he was pulling a big boat or trailer whatever???)

28c will prevent ping but means no added base possible which the performance cam must have to make TQ at low rpms...

changing the cent is a diy,,,your going to have to pull the dist to do the cam swap so fix the dist then...
???? until then just don't use OD (which is likely how the previous owner was driving it to have decent performance just due to more rpms)

when you get to that point start a new thread for tips and tricks to make changing the accel cent simple (because the instructions are clear as mud)...
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  #222 (permalink)  
Old 02-24-2010, 03:49 PM
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you bet! I may set it back the way it was since there was no pinging. This summer I hope to be able to set this thing up as a friendly daily driver. I drove last week with no lock out and the temps were fine. I also tried a week using third and the gas mileage was awful! Down to almost 10mpg or an extra 3 gal per fill up.

Thanks for the help!
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  #223 (permalink)  
Old 02-27-2010, 08:06 AM
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For fear of retaliation on this ongoing topic, I didn't want to post this question....but...if you don't like it...don't read it any more!

Hey Red, any chance a high rpm torque converter might contribute to the 55mph/lockup load? Any kind of test I can do to guestimate what kind of converter I have?
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  #224 (permalink)  
Old 02-27-2010, 08:24 AM
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ya got it backwards...

a higher rpms convertor rated "stall" means it doesn't grab 100% until higher rpms,,,(like slipping a clutch and gunning the motor to get going on a steep hill)...

yours is behaving like a oem stall rated convertor (engaged fully at about 1800) based on the in park/in drive Hg readings test you did back when...

your OD cruise rpms are so low due to the tires and gears a high(er) stall convertor would slipping constantly and generating a gazzillion btu's (due in part to the 4000lbs)...

I asked you to do that test to be sure you didn't have a high stall convertor,,,the tranny won't last with the present set up mis-matches...

ps: do remember that it takes me 10 edits to explain anything....
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  #225 (permalink)  
Old 02-27-2010, 08:30 AM
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Quote:
Originally Posted by red65mustang
ya got it backwards...

a higher rpms convertor rated "stall" means it doesn't grab 100% until higher rpms,,,(like slipping a clutch and gunning the motor to get going on a steep hill)...

yours is behaving like a oem stall rated convertor (engaged fully at about 1800) based on the in park/in drive Hg readings test you did back when...

your OD cruise rpms are so low due to the tires and gears a high(er) stall convertor would slipping constantly and generating a gazzillion btu's (due in part to the 4000lbs)...

I asked you to do that test to be sure you didn't have a high stall convertor,,,the tranny won't last with the present set up mis-matches
Got it!! That sounds better, and now I remember the test!!!!!
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